This invention relates to novel waterdispersible polymeric compounds and more particularly to blends of water-dispersible melamine/formaldehyde and/or urea/formaldehyde resins with cationic water-soluble polymeric amine compounds which are useful in the treatment of aqueous liquids to remove undesired suspended matter.
The removal of suspended matter from aqueous systems by the use of chemical agents has been practiced for many years. This treatment has been used to recover valuable solid materials from water, for instance, after water washing steps in mining operations and in emulsion polymerization. Treatment with chemical agents has also been used to purify aqueous systems, such as effluent water from industrial waste treatment facilities and from sewage treatment plants.
The most widely used class of water treatment chemical agents are the cationic agents. In the past, it was customary to use substances such as alum and ferric salts for this purpose. However, these salts leave a lot to be desired from the standpoint of efficiency and overall cost. High molecular weight polymeric compounds have been found to be quite efficient for the removal of suspended matter from aqueous systems. For example, it is known to use water-dispersible melamine or melamine-formaldehyde resins to remove suspended solids from water. Cationic polymers such as polyquaternary ammonium compounds have also been used for this purpose.